1. Field of the Invention
This invention relates to the field of dot-matrix printing and more particularly to systems for dot-matrix printing using a printing head having two columns of dot forming elements.
2. Prior Art
A dot-matrix printer is one which forms characters from a plurality of dots arranged in rows and columns. One format known in the prior art utilizes a 7.times.7 matrix, that is, a matrix 7 dots high by 7 dots wide.
A conventional way of printing such characters is to force the ends of wires, or styli, into contact with a printing medium such as an inked ribbon, which in turn makes dot marks on paper. The arrangement of the dots within the matrix conveys the form of the characters. The styli are electromagnetically driven and one popular embodiment includes the styli arranged in columnar form, i.e. a column of 7 styli, the columns being printed sequentially. The line is scanned at constant speed and the styli are actuated at the appropriate times to form the desired characters.